Jazzar was a Christian slave boy from Herzegovina who, escaping after committing a murder, sold himself to the slave-markets of Constantinople. There he was bought by an Egyptian ruler who converted him to Islam and used him as his chief executioner and hit-man. He began his rise as governor of Cairo but made his name defending Beirut against Catherine the Great's navy. Beirut was honorably surrendered to the Russians after a long siege and the sultan rewarded al-Jazzar with promotion to Governor of Sidon, and sometimes also that of Damascus. Jazzar set up his capital in Acre after the fall of Dhaher al-Omar. He earned the nickname "the Butcher" for his bravery and brutal effort to defeat his enemies. He is reputed to have walked around with a mobile gallows in case anyone displeased him.

Jazzar led a ruthless 'holy war' (jihad) campaign against non-Muslims. Under his ruled, Christians were forced to "accept" Islam. He oppressed minorities in Palestine including Christians (who were massacred) and Jews.

Jazzar is best known for defending Acre against Napoleon Bonaparte during the siege of Acre in 1799. After Napoleon's capture of Egypt, then an Ottoman territory, the French army attempted to invade Syria and Palestine. Although the French captured Al-Arish and Jaffa, and won every battle they fought against the Ottomans on an open field, they were unable to breach the fortifications of Acre. Their army was weakened by disease and cut off from resupply. The success was due to the English Commodore William Sidney Smith too, who sailed to Acre and helped the Turkish commander reinforce the defenses and old walls and supplied him with additional cannon manned by sailors and Marines from his ships. Smith also used his command of the sea to capture the French siege artillery being sent by ship from Egypt and to deny the French army the use of the coastal road from Jaffa by bombarding the troops from the sea.

Though both Napoleon and Jazzar requested assistance from the Shihab leader, Bashir, ruler of much of present-day Lebanon, Bashir remained neutral. After several months of attacks, Napoleon was forced to withdraw and his bid to conquer Egypt and the East failed.

With the help of his chief financial adviser, Haim Farhi, a Damascus Jew, Jazzar embarked on a major building program in Acre that included fortifying the city walls, refurbishing the aqueduct that brought spring water from nearby Kabri, and building a large Turkish bath. One of the most important landmarks built by Jazzar was the mosque that bears his name, a massive building in the Turkish style. Built over a Crusader church, the Al-Jazzar Mosque incorporates columns brought from Roman and Byzantine ruins in Caesarea and Tyre, and included a school for Islamic religious studies, later used as a religious court. Al-Jazzar and his adopted son and successor Suleiman Pasha, were buried in the courtyard.